Chair, in particular office chair

ABSTRACT

A chair has a frame, a seat plate which is mountable on a frame and is inclinable by a weight displacement, the seat plate has a front half which is turnably connected with the frame, and a location which is arranged further to the back and is connectable in articulated manner with the frame, a lever articulately connecting the location of the seat plate with the frame, at least one leg spring mounted under the seat plate on the frame and applying a return force to the seat plate, and an abutment on which the seat plate, depending on a body weight of a stool user, is adjustable.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a chair, in particular an office chair, with a seat plate which is mounted on a frame and can be inclined by a weight displacement.

[0002] The seat plate of such chairs can be inclined downwardly by a chair user, by leaning against the back with its body weight against the spring force in the rear region. The spring force can be adjusted individually in correspondence with the body weight of the chair user, so that a lighter chair user as well as a heavier chair user can incline downwardly the seat surface exclusively by its body weight, without pressing additionally for example from a table edge or the like. On the other hand, a chair user can adjust the return force of the spring so that the seat surface is inclined downwardly relative to the back by a stronger leaning. The adjustment of the return force was performed by a rotary knob mounted under a seat surface.

[0003] When for example a lighter person is seated on the chair and subsequently a heavier person sits on the chair the return force can be adjusted in accordance with their desires. For this purpose, they must turn the adjusting knob relatively frequently until the desired return force is adjusted. This relatively frequent turning of the adjusting knob is considered by chair users as very uncomfortable.

SUMMARY OF THE INVENTION

[0004] Accordingly, it is an object of the present invention to provide a chair of the above mentioned general type which avoids the disadvantages of the prior art. More particularly, it is an object of the present invention to provide a chair of the above mentioned general type in which the adjustment of the return force of the spring is comfortable.

[0005] In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a chair of the above mentioned general type, in which the seat plate is connected with the frame turnably in its front half, and at a location of the seat plate which is located further to the back is connected with the hinge articulately through at least one lever. Also, at least one leg spring is mounted under the seat plate on the frame and applies a return force to the seat plate, and an abutment of the at least one leg spring is adjustable on the seat plate, depending on the body weight of the chair user. The adjustment of the abutment of the leg spring can be performed fast and conveniently without applying any force.

[0006] The adjustable abutment can be formed as a rod which is displaceable parallel to the seat plate and arranged between the seat plate and the front leg of the leg spring. In this case, the chair user can adjust the return force of the leg spring as he desires very simply and conveniently, by displacement of the rod along the chair.

[0007] The adjustment of the return spring is especially comfortable, when the displacable rod extends at least at one side laterally beyond the seat plate, in accordance with another feature of the present invention.

[0008] For increasing the seating comfort, the inclination of the back can be adjustable in a known manner simultaneously with the inclination of the seat plate. The back can be inclined more than the seat plate, which is more favorable from the ergonomic point of view.

[0009] An excessive lifting of the front edge of the seat plate during lowering of the rear seat plate region can lead to an undesirable pressure on the legs of the chair user. In order to avoid this, the inclination mechanics of the seat plate can be designed so that the seat plate in its front half is connected with a frame through at least one shackle which is turnably arranged on the seat plate. Then the whole seat plate during inclination is somewhat moved rearwardly. Alternatively to this, the seat plate can be turnable however in its front region around the turning axle which is fixed on the frame, and the connection between the seat plate and the frame which is located further behind in the longitudinal direction of the chair can be displaceable.

[0010] The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a side view of a seat plate and a frame of a chair in accordance with the present invention; and

[0012]FIG. 2 is a view of a rear region of the downwardly inclined seat plate in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013]FIG. 1 shows a seat plate 10 which is mounted on a frame 11 of a chair in accordance with the present invention. The seat plate 10 is downwardly inclinable in its rear region as shown in FIG. 2. In the front half, the seat plate 10 is connected with a frame 11 through a shackle 12 which is turnably arranged on the seat plate 10. At a location which is further behind, the seat plate 10 is connected articulately with the frame 11 through a lever 13.

[0014] A leg spring 14 is mounted under the seat plate 10 on the frame 11. The leg spring 14 applies a return force with its legs 19 and 20, to the seat plate 10 and presses thereby the seat plate 10 which is inclined downwardly in the rear region, during unloading again upwardly to the initial position. The leg spring 10 obtains its pretensioning, since the abutments 15 and 16 arranged on the seat plate press against its legs 19 and 20. The abutment 16 can be displaced along an elongated hole 17. With the displacement of the abutment 16 in the elongated hole 17, the pretensioning of the leg spring 14 can be individually adjusted. Thereby the return force of the spring 16 can be varied, depending on the body weight of the chair user. The abutment 16 in the initial position of the seat plate 10 shown in FIG. 1 has no contact with the leg 19 of the spring 14, which abuts against the frame 11. During inclination of the seat plate 10 shown in FIG. 2, the abutment 16 comes in contact with the leg 19. The leg 20, to the contrary, in all positions of the seat plate 10 abuts against it.

[0015] The abutment 16 in the shown example is formed as a rod which extends laterally beyond the seat plate 1. The back of the not shown chair can be mounted on the extension 18 of the lever 13. During inclination of the seat plate 10 shown in FIG. 2, the not shown back or the extension 18 are inclined simultaneously with the seat plate 10. However, the back or the extension 18 are inclined more than the seat plate 10. This is favorable ergonomically for the chair user.

[0016] It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

[0017] While the invention has been illustrated and described as embodied in chair, in particular office chair, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

[0018] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. 

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:
 1. A chair, comprising a frame; a seat plate which is mountable on a frame and is inclinable by a weight displacement, said seat plate having a front half which is turnably connected with said frame, and a location which is arranged further to the back and is connectable in articulated manner with said frame; a lever articulately connecting said location of said seat plate with said frame; at least one leg spring mounted under said seat plate on said frame and applying a return force to said seat plate; and an abutment on which said seat plate, depending on a body weight of a stool user, is adjustable.
 2. A chair as defined in claim 1 , wherein said abutment is displaceable and formed as a displaceable rod located between said seat plate and a front leg of said helical spring.
 3. A chair as defined in claim 2 , wherein said displaceable rod extends outwardly beyond said seat plate at least at one side.
 4. A chair as defined in claim 1 ; and further comprising a back which is inclinable simultaneously with inclining of said seat plate so that an inclination of said back is greater than an inclination of said seat plate.
 5. A chair as defined in claim 1 ; and further comprising a shackle which is turnably arranged on seat plate and connects said front half of said seat plate with said frame.
 6. A chair as defined in claim 1 ; and further comprising a turning axle which is fixed on said frame, said seat plate being turnable in a front region on said turning axle; and a connection provided between said seat plate and said frame further behind and displaceable in a longitudinal direction of the chair. 